The closest prior art has been described in the device according to USSR Inventors' Certificate No. 1288747, Int.Cl. G 09 F 3/03, 1984, which comprises a body with a head, a fixing and a locking element, wherein the fixing element is made in the form of a case and a stop, the locking element is made in the form of a spring.
Of the major drawbacks of said device is a complexity of its manufacture associated with a complicated threading inside a nut. Moreover, the use of a specific tool is needed to lock the device, which is inconvenient during use; the more so, as it is necessary to simultaneously hold up the nut and the casing with one hand on the inside of a lug of an object being locked, whereas the other hand serves to apply a specific tool to a body's head on the outside of said lug of an object being locked. The known device is of no use during possible displacement of a lug in railway wagons and can not be used for seal-locking of cargo transportable in railway wagons and containers. Its individual manufacture is needed for using in objects with different dimensions of lugs and distances between them, which creates difficulties and drawbacks during operation.